Graphite ribbon

Phenacenes are a family of graphite ribbons , where benzene rings are fused together in an alternating pattern. Phenanthrene is the simplest member of this family and other members include the 22-electron system picene (91), the 26-electron system fulminene (92), and the larger member of this family, the 30-electron [7]phenancene, with seven rings (93). ... 

Mallory, F.B., Butler, K.E., and Evans, A.C. (1996) Phenacenes a family of graphite ribbons. 1. Syntheses of some [7]phena-cenes by stilbene-like photocydization. Tetrahedron Letters, 37, 7173-7176. 

An all carbon conjugated ladder polymer (graphite ribbon) was synthesized by a novel electrophile-induced cyclization reaction to provide fused benzenoid aromatic hydrocarbon in quantitative yield [161]. Suzuki cross-coupling of dieneyne 105 with 1,4-didode-cylbenzene-2,5-diboronic acid (106) gave rigid-rod polymers 107, which was further treated with TFA to produce 108 graphite ribbon as a yellow/orange solid. 

Figure 1.13 The structure of glassy carbon. The entangled graphitic ribbons give rise to extraordinary rigidity and isotropic materials properties ( Cambridge University Press 1976).

Several different electrothermal atomizers such as carbon rod, graphite ribbon, graphite furnace, and metal loop atomizers, have been designed for AFS measurements. In general, the electrothermal atomization method is time-consuming and expensive with respect to flame atomization. It is, thus, appropriate to use electrothermal atomization only when the sample amount or analyte concentration restrict the use of flames or plasmas. 

Another example of Ji-conjugated materials is graphite ribbons (Eq. 80). Polymerization by the biaryl-coupling strategy is followed by... 

Wu J, Gherghel L, Watson MD et al (2003) From branched polyphenylenes to graphite ribbons. Macromolecules 36 7082-7089. doi 10.1021/ma0257752... 

During carbonization of PAN, an extensive-random network of graphitic ribbons is formed which heis a stable configuration. I n addition, it is speculated that some tetrahedral (sp (diamond) bonds are formed (which would account for the hardness of these materials). 1 1 The presence of diamond structure in a similar material, diamond-like carbon, is well established (see Ch. 14). The diamond structure is reviewed in Ch. 2, Sec. 3.0. These two factors, ribbon network and tetrahedral bonds, would preventfurther ordering ofthe staicture, regardless of the graphitization temperature. 

This random structure, characteristic of vitreous carbon, is believed to have the form of an extensive and stable network of graphitic ribbons, shown in the simplified schematic of Fig. 6.5.( i These ribbon-like tangled aromatic molecules are cross-linked by carbon-carbon covalent bonds with varying bond energies. Some of these bonds may be highly strained.l l... 

Figure 8.24 Schematic representation of different types of carbon nanofibres (a) graphitic platelets, (b) graphitic ribbons, (c) graphitic herringbone, (d) single-walled nanotube and (e) multi-walled nanotube.

Pisani, L., Chan, J. A., Montanari, B., 8c Harrison, N. M. (2007). Electronic structure and magnetic properties of graphitic ribbons. Physical Review... 

While the insolubility of the resulting graphite ribbons 60 precluded standard spectroscopic structure elucidation, their electronic and vibrational properties were... 

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